assume cs:codesg,ds:datasg

datasg segment
	x dw 30
	y dw 15		;定义初始x，y，z
     z1 dw ?
     z2 dw ?
     z3 dw ?
datasg ends

codesg segment
start:mov ax,datasg
	mov ds,ax      ;将数据存入数据段

	mov ax,x	;ax = x
	add ax,y	;ax = ax + y
	mov z1,ax	;z1 = ax

	mov ax,x	;ax = x
	sub ax,y	;ax = ax - y
	mov z2,ax	;z2 = ax

	mov ax,x	;ax = x
	mov bx,y	;bx = y
	mul bx		;ax = ax*bx
	mov z3,ax	;z3 = ax

	mov ax,4c00h
	int 21h
codesg ends
end start